A holiday-maker is more affected (6)
I believe the answer is:
camper
I believe this clue is a double definition.
'a holiday-maker' is the first definition.
(someone on a camping holiday)
'more affected' is the second definition.
(camp can mean affected or theatrical)
'is' acts as a link.
(Other definitions for camper that I've seen before include "more affected?" , "Touring vehicle" , "Overnight van" , "Large motor vehicle with beds, cooker etc" , "Vehicle for living in" .)